May, 1923
INDUSTRIAL AND ENGINEERING CHEMISTRY
A discussion of this sort is apt to prove disappointing in that it fails to specify definite requirements. It states what is better and what is worse rather than what is right and what is wrong. It is hoped, however, that the discussion may have thrown some light on the various requirements of internal-combustion engines and their relative importance.
Economic Aspects of Motor-Fuel Supply fiom Petroleum’ By F. W. Lane and A. D. Bauer BUREAUO F MINES,WASHINGTON, D. C!
I
T IS EVIDENT to all who have to review chemical literature that. there are periodic waves of interest in particular subjects, or in various aspects of these subjects. At one time there is a large number of articles on some one topic, whereas a few months later the center of interest has changed entirely. In no field is this more true than in the petroleum industry. If we look back over the past fifteen years we find that there has been a steadily growing output of books and articles dealing with the economic aspects of this industry. At first these articles were largely descriptive, telling how the various products were made and used; then there began to appear a note of alarm-it was feared that the supply of c p d e oil was insufficient and that the demands made upon it would become too great. Of course, the war with its tremendous consumption of petroleum products intensified this alarmist literature and it continued to increase in size and importance up to the end of 1920. It seemed to be general throughout the petroleum industry, some of the ablest executives joining in the chorus. All of a sudden something happened. The price of crude oil dropped with a suddenness which shook the industry from top to bottom. As soon as the excitement caused by this sudden change subsided the industry tried to find out what really had occurred, and in the past two years a feeling has apparently grown up that our supplies of crude oil are inexhaustible, that all this alarmist literature was a mistake, that we are going to have sufficient oil for all our needs for ai1 indefinite period. Within the past thres months, however, the price of crude oil, at least east of the Rocky Pllountains, has begun to rise again, and the increases have been so frequent that the industry is again trying to take stock of what has happened. It is not necessary to go into details of the actual production by fields, but the statistics of the past few months indicate the following things. In the first place, California is producing a large excess of relatively high-grade oil, with the result that a considerable amount of California crude is being transported to the east coast by way of the Panama Canal for refining. In a way this seems to be providential, as this California crude is taking the place of the Mexican oil previously used, the past year having seen the beginning of a great decline of production in Mexico. Aside from California, however, the situation is not as hopeful as we might wish. There have been tremendous developments in Arkansas, but practically all the oil SO far produced a t Eldorado and Smackover is of the socalled “fuel-oil” grade. It is fairly high in sulfur and very little of it is used for the production of gasoline. On the other hand, the production in the Midcontinent district of the so-called “light crude”-that is, crude with a high gasoline content-seems at the present time to be very slowly declining, Published by permission of the Director, Department of the Interior, Bureau of Mines.
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Prophecy is impossible, however, at least in details. We may at any time find new fieIds of light crude which will more than make up for the probable decline of the present producing fields. If such fields are not developed, however, it looks as if economy in the use of gasolioe and the development of possible substitutes will become more and more necessary.
HISTORY OF GASOLINE INDUSTRY It was in the nineties of the last century that gasoline was first used as fuel for road vehicles. A few steam carriages were built in earlier years, but they were not very successful, and until the internal-combustion motor was developed and placed on rubber-tired wheels the self-propelled road vehicle was only an inventor’s dream. The first successful automobiles used what was called “benzine” in those days, which was a by-product of the kerosene industry. This “benzine” or “gasoline,” as it soon came to be called, was a good deal like the “fighting gasoline” furnished our aviators at the front, which was designed to give extra speed and power in airplane motors specially tuned up to its use. For several years the quality of gasoline remained about the same. Then it began to be apparent that the supply must be increased. More cars were being put on the road every day, and as the demand increased the refiners were forced t o begin cutting deeper into the crude oil and putting more of it into the gasoline fraction. How far this process has gone is well known to every driver who remembers the gasoline of ten or twelve years ago. How much further it will go is a question on which some of our best technical men are working. It is doubtless true that we can use gasoline even less volatile than the present grades, but the steadily increasing demand for kerosene may make it necessary to stop raising the end-point of gasoline. In other words, there is an economic volume between the supply of straight run gasoline and kerosene. The last ten years have seen other changes in the character of gasoline. The refiners found that they would have t o make more motor fuel than could be recovered by ordinary distillation practice, and proceeded to do so by means of the so-called “cracking” processes. Gas oil, which lies between kerosene and lubricating oil in volatility, when heated under pressure will break down or “crack” to form gasoline. The early experimenters encountered difficulties such as too great a formation of fixed gases and carbon, which cut down the efficiency of the processes used and added to the expense of operation. Continued research, however, reduced these losses, and cracking is now being done at a profit. It is estimated that at least 20 per cent of our motor fuel is produced to-day in cracking stills. About the same time that the refiners began to add to the size of the gasoline fraction, thus raising the end-point of the resulting motor fuel, the manufacture of natural-gas gasoline was started. This material is very volatile and is carried as vapor by natural gas, but it can be removed in the liquid state if the gas is highly compressed and then cooled. It has proved to be a valuable addition to our gasoline, as it furnishes a much needed supply of low-boiling hydrocarbons which are lacking in many grades of crude oil. While natural-gas gasoline amounts to onlyabout 10 per cent of our total gasoline supply, it makes available as motor fuel a large amount of material that would otherwise be useful only as naphtha for solvent purposes. The older processes for making natural-gas gasoline depended on compression and refrigeration, but more recent ones have been developed in which the gas is passed through heavy oil or charcoal, which absorbs the gasoline. This is then recovered by distillation.
INDUSTRIAL AND ENGINEERING CHEMISTRY
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METHODS O F INCREASING GASOLINE SUPPLY
Vol. 15, No. 5
fuel, they certainly show that it will be well first to investigate thoroughly our mineral resources, Therefore, the three principal methods that have been CoAL-Although crude petroleum is paramount in imused in the last ten years to increase the supply of gasoline have been-first, raising the end-point; second, cracking portance, there are several other mineral sources. of motor gas and fuel oil; ana third, making use of natural-gas gasoline. fuel. Of these, the most valuable to-day is coal, from which As already stated, it may not be possible to raise the end- we obtain benzene. Commercial benzene is a mixture of point much higher, on account of the demand for kerosene. volatile hydrocarbons and is made as a by-product of the We cannot hope for a great increase in natural-gas gasoline, coke industry, either by distilling coal tar, or by passing coal as the supply of natural gas is more likely to decrease than gas through absorbing towers. It is a good motor fuel when to increase as time goes on. The processes of cracking usually used alone, and has especial value when mixed with gasoline employed are limited by economic considerations. If the as it tends to prevent detonation. It must, however, be price of gas oil is low and the price of gasoline comparatively properly refined. When benzene was first used in this country high, it pays the refiners to use cracking stills. There are, asza motor fuel the excess of sulfur contained in it caused however, other large and important uses for gas oil, and its corrosion of the needle valves and other exposed parts of price therefore tends to rise until cracking ceases to be the carburetors. The manufacturers have learned how to remove this dangerous excess of sulfur, and most benzene profitable. of to-day is free from this fault. The supply, however, is NEEDFOR FURTHER INCREASE OF MOTOR-FUEL SUPPLY limited. It has been estimated that the maximum development of the coal-tar industry possible in ten years will inDuring the past several years our gasoline production has crease the production of benzene to 350,000,000 gal. per increased by leaps and bounds, as is shown by the following year, which is only about 6 per cent of our present motorfigures: fuel requirements. PRODUCTION OR GASOLINE IN GALLONS OIL SHALE-while coal is the one mineral, aside from 1904 petroleum, from which we are getting motor fuel a t present, 1909 1914 it may be of less ultimate importance in this regard than 1916 1917 oil shale. Much has been written about the vast deposits 1918 of shale, particularly in the West, and there seems to be 1919 1920 little question but that eventually there will be a great and 1921 1922 flourishing industry founded on this mineral. It has been estimated that there are locked up in the shale beds stores During December, 1922, the refineries produced more gas- of oil many times as large as the total recoverable oil in the oline than ever before recorded, but in spite of this large sands. But a t the present time the shale-oil industry is in increase in supply we have consumed the gasoline as fast the experimental stage, and we are still in the process of as the industry has been able to produce it. Motor cars, acquiring the fundamental knowledge and technic necessary trucks, and tractors are the main consumers of gasoline, to enable us to make high-grade oil on a commercial scale. and a glance a t the production of automobiles and trucks The manufacture of oil from shale has been carried on for indicates where our gasoline has gone. years in Scotland, but the American shales are somewhat different in character, so that the Scotch methods are probPRODUCTION OF AUTOMOBILES AND TRUCKS 1910 187 000 ably not applicable in this country unless modified. The 1915 892:618 mainstay of the Scotch shale industry is the yield of ammonia, I916 1,683,617 1917 1 868 947 and the oil is more or less a by-product. American shales 1918 1:153:637 1919 1,974,016 do not yield muoh ammonia, and the industry will, therefore, 1920 2 205 197 have to make oil its main product, thus coming into direct 1921 I :668:550 competition with petroleum products. Accordingly, for a Thus, it seems that our gasoline consumption is limited long time to come, the price obtainable for shale oil will be set only by the amount available, for there is every indication by the prevailing prices for crude petroleum, and the best of a continued increase in the output of internal-combustion authorities agree that even though shale may eventually motors, and it is readily apparent that we need continually furnish most of our motor fuel, a t the present time it is only increasing supplies of motor fuel. in favored localities and under the most careful management that a shale-development company can succeed. POSSIBLE NEW SOURCES OF MOTOR FUEL POSSIBILITIES IN VEGETABLE KINGDOM-If, then, the ALcoHoL-Must we turn to the vegetable kingdom and resources of the mineral kingdom outside of the field of crude depend on alcohol and similar fuels? Fortunately, it is petroleum are limited, either in quantity or on account of not yet necessary to do so. Fortunately, because while our present lack of knowledge or by economic conditions, the motor fuel that can be made from vegetable matter is what do we find on investigating the vegetable kingdom? replaceable-that is, while we can grow new crops each year One outstanding fact-that most vegetable products already that will yield alcohol-in most cases we can do so only a t have important uses, and the only materials that can be economically used for the production of motor fuels are the a tremendously increased cost. For example, the corn that can be grown on an average acre of Oklahoma soil in a year vegetable wastes of to-day, or are plants that can be grown will yield about 3 bbls. of alcohol. Many of the oil fields on land that is not now needed for other purposes. As of Oklahoma have an ultimate production of about 3500 bbls. already stated, it would take three hundred years to grow of crude petroleum per acre, of which about 1000 bbls. can be enough corn in the oil fields of Oklahoma to obtain a volume considered as gasoline. One would have to grow corn on of alcohol equivalent to the production of gasoline obtainable a n acre of Oklahoma oil land for about three hundred years in a few years. Of course, the area of the oil fields in the to obtain a volume of alcohof equal in fuel value to a supply country is but a small part of the total area of the United of gasoline produced in from five to ten years. While these States, but this simply emphasizes the fact that while we can figures are limited in application and are not intended to grow corn over an area many times as large as the area of discourage attempts to develop vegetable sources of motor the producing oil lands, it will then have to be harvested PAST
May, 1923
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INDCSTRIAL A N D ENGIIC’EERISG CHE3IISTRY
and brought to the distilleries, a laborious and expensive task. Furthermore, edible grain of any kind is usually too valuable to be used for the manufacture of alcohol. And even if we had a surplus it would be a mere drop in the bucket. A surplus of 1,000,000,000 bu. of corn would sound tremendous to the farmers of this country, but it would yield only 250,000,000 gal. of motor fuel, enough to run our cars and trucks about three weeks. The same reasoning applies to all other sound grains, vegetables, and fruits. At present they are too valuable as food for man or for stock feed to be used to makemotor fuel, and if there were a surplus available it would be too small to be of much importance ‘in the aggregate supply. The case is somewhat different with waste products. According to the records of the Department of Agriculture, this country produced 286,085,463 gal. of alcohol, mostly from waste molasses: during the fiscal year ending June 30, 1917, when production was stimulated to its highest point. The other large source of vegetable waste is the lumber industry. Although a good deal of experimenting has been done, little alcohol has been produced from wood waste, as the process is rather complicated, and also because the yield is small compared to the yield from molasses. The Forest Products Laboratory estimates, however, that there is enough wood waste available every year in this country t o produce 240,000,000 gal. of alcohol. It is variously estimated that this country could, if necessary, produce from 500,000,000 to 1,000,000,000 gal. of alcohol, or from 8 to 16 per cent of our present motor-fuel needs.
MOST HOPEFUL METHODS OF PROVIDING FOR FUTURE NEEDS But the most important aspects of the motor-fuel problem have still to be discussed. Liquid fuel obtained from coal and lignite is good as far as it goes, but the supply is small as it is a by-product, and its production depends on the utilization of the coke produced at the same time; shale oil is of great future but little immediate value; alcohol from vegetable sources will always be limited in quantity, and cannot be produced to-day at a price to seriously compete with gasoline. The three methods that the refiners have employed up to the present time to get more gasoline have been shown to be inadequate to provide for all our future needs, but there are other methods available to the petroleum industry which seem to offer great hopes for the future. One method is to use gas oil directly as motor fuel. Cracking involves a loss of material and requires the consumption of fuel. For instance, if we crack gas oil me lose part of the total heating value of the oil and in addition consume other fuel in the cracking distillation. Obviously, if the gas oil can be used in an internal-combustion engine, we save these losses. It is gratifying to see that work is actively progressing in developing wtomotive engines to use heavy oils. Another method is to discover new oil fields. If we could be sure of finding a new Cushing or a new Burbank field every year or two, we would not have to worry a t all about substitutes for gasoline. Unfortunately, this is not as easy to do as it is to recommend, but as long as new production is found as fast as it is needed all will be well. But even today we are importing part of our oil, and we probably will continue to do so in larger and larger amounts. Undoubtedly, the undeveloped areas of the world contain large oil fields, but other nations are awake to the need of oil and only a part of these resources will be available for us. But there are other ways in which production can be increased. Wells that have been abandoned are to-day being repaired and are again producing oil in paying quantities. Large-scale experiments have shown that whole properties
can be reworked with modern methods, and in some cases in Ohio, Pennsylvania, and West Virginia as much oil has been recovered as was done before the properties were considered ready for abandonment. Furthermore, after the oil is above ground a great deat can be done to conserve it. A recent investigation of the Bureau of Mines disclosed large losses of oil by evaporation between the well and the refinery. The material that was lost was principally the best portion of the gasoline contained in the crude, and if saved, as much of it can be by proper methods of handling, it would add materially to the quantity and value of our gasoline. Similar losses occur in many phases of the transportation and refining of crude oil and gasoline, and the aggregate preventable loss is enormous. If, then, the producer and refiner of oil have it in their power to increase the amount of gasoline, and if this can be added to by other sources, as already shown, will there be enough motor fuel for our future needs? There will be if the automotive engineers, and especially if the public that drives cars, cooperate. It is gratifying to see the great interest that has developed recently in conservation and efficient utilization of all petroleum products, especially of gasoline. The public is becoming aware of the folly of using rich mixtures, and of running with one cylinder missing. Steps are being taken by the associations of oil refiners and automotive engineers to get together in a spirit of cooperation and mutual assistance, and solve some of the larger problems involved. These leaders in the petroleum and automotive industries realize that, while there may be supplemental fuels, still it is to petroleum that we must look for our motor-fuel supply, and the possibility of furnishing this needed motor fuel rests upon the producers and refiners of crude oil, who must seek increased production. But at the same time all must practice conservation to the utmost in order to utilize effectively all of this precious resource that we now have.
Use of the Bunsen Valve in Connection with a Filter Pump’ By Fred W. Ashton STRUCTURAL MAWRIALS RESEARCH LABORATORY, LEWISINSTITUTE, CHICAGO, ILL.
During the course of some recent work, the author was using “vacuum” subject to considerable fluctuation, due both to variation in water pressure and to variable “pull” by anothe? worker. The annoyance and difficulties caused by these variations were successfully overcome by the use of the Bunsen valve.
-77i------; t pum
toflask
C
D
A
A is the regulation safety bottle used to prevent the backing up of water from the pump. B is the bottle for the Bunsen valve. C is an extra 2.5-liter bottle for “capacity.” The valve is placed on the tube leading to this bottle. With this arrangement a fairly high vacuum can be maintained in the flask, even with almost complete momentary stoppage of the pump or temporary opening of the line on the pump side of the valve. 1
Received April 11, 1923.
